NXP Semiconductors MRF7S21110HR3

Overview

MRF7S21110HR3 from Freescale Semiconductor is a laterally diffused N-channel enhancement-mode RF power MOSFET designed for CDMA and W-CDMA base station amplifiers operating at 2110–2170 MHz. It delivers 33 W average output power at 28 V with 17.3 dB power gain and 32.5% drain efficiency under single-carrier W-CDMA conditions, and supports digital predistortion correction in multicarrier cellular infrastructure.

For engineers reviewing the MRF7S21110HR3 datasheet, MRF7S21110HR3 pinout, MRF7S21110HR3 application, or MRF7S21110HR3 equivalent, key selection criteria include its 2140 MHz broadband performance, 10:1 VSWR ruggedness, 110 W CW P1dB capability, integrated ESD protection (HBM Class 1B), and NI-780S package thermal resistance of 0.41 °C/W at 33 W.

Technical Context

This device operates in Class AB and Class C configurations for PCN/PCS/cellular radio and wireless local loop (WLL) systems. Its internally matched input and output enable direct integration into 50 Ω test fixtures without external matching networks, and it is characterized using series-equivalent large-signal impedance parameters (e.g., Z_source = 2.1 − j4.7 Ω, Z_load = 2.0 − j3.5 Ω at 2140 MHz).

The MRF7S21110HR3 features a gate threshold voltage of 1.2–2.7 V, supports −6.0 to +10 V_GS, and is rated for continuous operation up to T_J = 225 °C. Its design includes enhanced negative gate-source voltage range for stable Class C operation and is optimized for digital predistortion (DPD) error correction, achieving −38 dBc ACPR at ±5 MHz offset in 3.84 MHz channel bandwidth.

Key Specifications

Pinout & Package

The MRF7S21110HR3 is housed in the NI-780S package (Case 465A-06, Style 1), a ceramic/metal flanged package with solderable baseplate for low-thermal-resistance mounting. It features three terminals: Drain (case), Source (pin 1), and Gate (pin 2), with the metal case electrically connected to the drain for RF grounding and thermal conduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power transistor applications.

Compared with MRF7S21110HSR3, the MRF7S21110HR3 offers identical RF performance but optimized tape format for lower-volume or mixed-SMT production; versus AFM905S, it provides +13 W avg. output and superior thermal resistance at the cost of slightly reduced gain and broader bandwidth tolerance.

Availability

MRF7S21110HR3 is available at Aetrix Electronics and suitable for CDMA base station power amplifiers, W-CDMA macrocell transmitters, Doherty carrier paths, digital predistortion reference units, and wireless local loop (WLL) infrastructure requiring stable component supply across extended temperature and RF stress conditions.

Supply support for MRF7S21110HR3 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in RF power solutions for wireless infrastructure, automotive radar, and industrial heating applications.

The MRF7S21110HR3 belongs to Freescale's LDMOS RF power transistor family, engineered specifically for high-efficiency, high-linearity cellular base station amplifiers operating in the 2–2.2 GHz band.

FAQ

What is the maximum continuous drain current rating for the MRF7S21110HR3?

The MRF7S21110HR3 does not specify a maximum continuous drain current (I_D) rating independent of thermal conditions. Instead, its safe operating area is defined by junction temperature (T_J ≤ 225 °C), case temperature (T_C ≤ 150 °C), and thermal resistance (R_θJC = 0.41 °C/W at 33 W). At 28 V and 1100 mA quiescent current, the device delivers 33 W avg. output in W-CDMA operation, and its P_1dB point occurs near 110 W CW - corresponding to peak drain current exceeding 4 A under pulsed conditions. Designers must use the MTTF calculator and AN1955 thermal methodology to validate current derating per application.

Does the MRF7S21110HR3 require external matching networks for 50 Ω systems?

No, the MRF7S21110HR3 is internally matched for both input and output in 50 Ω systems, as confirmed in Table 4 footnote and Figure 15 impedance data. Its source impedance is 2.1 − j4.7 Ω and load impedance is 2.0 − j3.5 Ω at 2140 MHz, and Freescale's test circuit (Figure 1, Table 5) achieves full performance without discrete matching components. However, narrowband optimization or harmonic suppression may still require external filtering, especially in multicarrier Doherty or envelope-tracking configurations where impedance varies dynamically.

What ESD protection level does the MRF7S21110HR3 provide, and how is it verified?

The MRF7S21110HR3 provides Human Body Model (HBM) Class 1B (≥500 V), Machine Model (MM) Class A (≥200 V), and Charge Device Model (CDM) Class IV (≥1000 V) ESD protection, per Tables 3 and 4. These ratings are verified through standardized JEDEC/ESDA test methodologies during production screening. The integrated protection is implemented via on-chip diode structures between gate and source/drain, enabling robust handling during PCB assembly and field deployment without requiring additional external TVS devices on the gate line.

Can the MRF7S21110HR3 be used in Class C amplifier topologies, and what design considerations apply?

Yes, the MRF7S21110HR3 is explicitly designed for Class C operation, featuring an extended negative gate-source voltage range (V_GS down to −6.0 V) to improve switching behavior and efficiency in nonlinear modes. When operated in Class C, designers must ensure gate drive circuitry can deliver stable negative bias, verify thermal margin given higher peak currents, and confirm that the 10:1 VSWR ruggedness remains valid under highly reactive load conditions typical of tuned tank circuits. Freescale's application notes EB212 and AN1955 provide layout and thermal guidance for such implementations.

What is the recommended gate bias voltage for linear W-CDMA operation of the MRF7S21110HR3?

The recommended gate quiescent voltage (V_GS(Q)) for linear W-CDMA operation is 2.0–3.5 Vdc, with a typical value of 2.7 Vdc at V_DD = 28 V and I_DQ = 1100 mA, as specified in Table 4. This bias point establishes the optimal trade-off between gain, linearity (ACPR), and efficiency. Deviations outside this range increase IMD distortion or reduce output power; for example, lowering V_GS(Q) to 2.0 V increases gain but degrades ACPR by ~2 dB, while raising to 3.5 V improves linearity at the expense of 0.8 dB gain loss. Bias stability over temperature is ensured by the device's low gain drift (0.011 dB/°C).